Designs Of Vibration Isolation And Noise Reduction For Diesel Power Generator Set

The vibration and noise of marine diesel engine power generator set affect the safety of marine structure and the reliability of equipment, and pollute the environment. For warships, the vibration and noise of marine power device influence the marine battle effectiveness and hiding capability, so the noise and vibration control technology for marine power devices is always important. The present study investigates the marine power device installed with acoustic enclosure and double resilient movinting, and calculates the vibration isolation efficiency with the finite element method, and calculates the sound isolation efficiency with the boundary element method.In vibration section, some ameliorative methods of vibration isolation are discussed: 1. the effects of different arrangement vibration isolators on the system structure mode and transmission loss rate are discussed. The results show us that the vibration isolation efficiency can be improved by changing isolators' location. 2. changing the flexible pipeline's rigidity and location influences vibration isolation efficiency. Increasing the flexibility pipeline's rigidity has negative effects on vibration isolation especially when the diesel set's rotate speed is low. 3. changing the mass of acoustic enclosure influences system structure mode and transmission loss rate. Increasing the mass of acoustic enclosure has active affect on vibration control.In noise control section, the acoustic mode inside the acoustic enclosure and the structure mode of two stage vibration isolation device is calculated, the influence of the noise isolation when considering the sound-solid interaction and the influence of acoustic enclosure radiated noise by middle mass vibration transmission is discussed. Because of taking the sound-solid interaction into account, there are more peak value in transmission loss curve. If supposing the middle mass is quiescence, the transmission loss curve is mainly influenced by acoustic mode inside the acoustic enclosure and theacoustic enclosure's structure mode. When the middle mass vibration transmission is taken into account, the transmission loss curve is influenced by middle mass's structure mode, acoustic mode inside the acoustic enclosure and the structure mode of power device. The structure strength of middle mass should be enhanced in design phase.